This application pertains to the art of slip joints, and more particularly to torque couplings or to bearings.
Examples of known slip joints include those disclosed in U.S. Pat. No. 2,199,926, issued May 7, 1940 to Swennes, and U.S. Pat. No. 3,066,503, issued Dec. 4, 1962 to Fleming et al. These joints have rubber interposed between inner and outer members. The outer member is deformed at a plurality of circumferentially-spaced locations before the joint is assembled. Therefore, very close tolerances are required to provide a very close sliding fit between all the parts so that the driving connection is not sloppy. Such close tolerances are difficult to maintain and make it difficult to economically manufacture the joints. In the Swennes joint, the rubber has a uniform thickness everywhere between the inner and outer members, and is bonded to one of the members to prevent the rubber from sliding axially out of the joint. In the Fleming joint, thin metal or plastic inserts are positioned between the rubber and the inner member. Fleming discloses that the rubber is placed under compression when the joint is assembled. With the rubber under compression, there is a considerable friction force between the inserts and inner member. In both the Swennes and Fleming devices, the rubber is relatively compressible so there would be substantial loss of movement when transmitting reversible torque because it is necessary to first take up the compressibility before torque is transmitted.
U.S. Pat. No. 3,550,232, issued Dec. 29, 1970, to Burnett discloses a method for making a bearing by deforming an outer ring around a ball while plastic material between the ring and ball is in its heat-softened state. Such an arrangement would make it difficult to prevent extrusion of the plastic material from between the two members when the deformation takes place. The plastic material in Burnett is also bonded to the ring member and this requires an additional manufacturing step.